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Jeffy
12-02-2007, 11:13 AM
I have the lower sorted out but I've yet to order an upper. I'm thinking about ordering a SDI 16" SST Fluted Mid-contour mid-length barrel with a 1:8 twist. The upper will also be a SDI. The handguard, a Troy MRF MX with a low-profile gas block. For the Flash hider, I'll go with a Vortex. The place I'm ordering from has a RRA BCG option for $105 but I'm thinking of using that to buy a Y/M BCG instead.

My original idea was to buy a Stag 2HT but wanted to be different and liked the 14.5's. So then I was looking at a 14.5" CMMG carbine upper but changed my mind since the the middy is highly recommended. Then I found that there aren't as many options available with prebuilt uppers as there are with the 16 which brought my to SDI.

So, am I doing alright with the upper? Or should I go a different route, change something, etc?

Thanks for your help.

Ryan HBC
12-02-2007, 11:54 AM
That sounds like a fantastic upper, especially for a first build. It sounds like you know what you're talking about, so any advice would only be opinions at this point.

My opinions, if you're going all out I would recommend against the Troy hand guard. Reason being, it is a little heavier and bigger than a Daniel Defense or Larue.

Some people may tell you to go with a chrome lined barrel instead of that Stainless one, but I think those fluted stainless SDI barrels are fantastic.

Jeffy
12-02-2007, 12:19 PM
Thanks. At least I seem to be going in the right direction. I only decided to go black a few months ago. Before that I didn't know much about AR's.

The only problem I have is that I'm trying to keep the cost down. (relative) I like that the Troy spans the delta ring. From what I've seen only the DD Lite they offer does that and at a considerable cost difference. It's $115 more for the Lite and $50 more for the regular. The lite pushes it a bit over my budget if I want a SDI receiver as well as a Vortex. If I forgo the Vortex ($40) I can get the DD.

I could maybe move up to the DD but then it have that interruption in the rail. For optics I was planning on a 1-4x on a LaRue SPR mount. Although I guess I could get an SPR-E but that again is more money. The other option is an Aimpoint but that would need to be on a cantilever mount.

The main thing I hate about AR's is that there are too many choices.

bwiese
12-02-2007, 12:21 PM
Troys are OK, but I'm far more impressed with my SWS rail on my Noveske N4 upper. Rock-steady.

Jeffy
12-02-2007, 12:31 PM
The SWS looks nice and not bad on the price. Although I should mention I'm looking at using a 10" rail and a Troy low-profile gas block. SWS doesn't seem to have a 10" rail, only an extended Carbine.

bwiese
12-02-2007, 12:45 PM
The SWS looks nice and not bad on the price. Although I should mention I'm looking at using a 10" rail and a Troy low-profile gas block. SWS doesn't seem to have a 10" rail, only an extended Carbine.

I'm pretty sure SWS does offer a rifle-length rail.

Jeffy
12-02-2007, 1:02 PM
I'm pretty sure SWS does offer a rifle-length rail.

Rifle length is going to be too long though, I think. The 10" should cover the gas block on a Middy from what I've read. I thought about going with a rifle length but it just looks a bit long for my taste.

bwiese
12-02-2007, 1:20 PM
Rifle length is going to be too long though, I think. The 10" should cover the gas block on a Middy from what I've read. I thought about going with a rifle length but it just looks a bit long for my taste.

I have a Troy rifle length rail on my SPR 18" and it looks fine: I have a rifle-position front sight with unused gas block, and a separate low-profile gas block in the middy position.

There are quite a few "Dissipator"-style rifles out there too: 16" bbls with rifle-length handguards, rifle-position front sights, yet having actual gas tap with a low-profile block under the handguards at the middy or carbine position.

Jeffy
12-02-2007, 3:03 PM
Yeah, I've looked into a Dissipater but I didn't want the long handguard look this time around. The 10" looks nice and proportionate without the front sight base. Not to mention I really like the SDI barrel.

As pre Ryan's advice, I think I might opt for the DD and forgo the
Vortex to help offset the added cost.

I still have to save up for a stock and BUIS as well. I wish Magpul would have still made the M93 but that doesn't seem to be the case. They have the CTR which I might end up with. The UBR seems like it will never come out and it's $$$.

BUIS, I'm thinking Troy although I would have liked to see allen head screws used instead of flat heads. PRI seems to have a decent BUIS that uses allens. I would have liked to use a LaRue rear BUIS but I want to use a scope and need flipups if I want them to be on the same rail.:mad:

Then there's the next expensive purchase, the scope. It's either going to be an Trijicon Accupoint, Leo MK4 MR/T, IOR 1.1-4x or maybe a USO SN4S. Again too many options...

I'm hoping to spread this build out over a few months so I can afford all the good stuff.

uscbigdawg
12-02-2007, 6:47 PM
On your barrel, reconsider the flutes. Very few people know how to cut them right and while the theory that it increases rate of cooling through increased surface area is sound, there are other options. Incorrectly cut flutes jack up the barrels harmonics and it won't shoot as well as it can.

On the optics, for all around use, ACOG's are tough to beat. A good TA01NSN will do everything you want. Larue QD mounts of course.

Rich

Jeffy
12-02-2007, 7:20 PM
On your barrel, reconsider the flutes. Very few people know how to cut them right and while the theory that it increases rate of cooling through increased surface area is sound, there are other options. Incorrectly cut flutes jack up the barrels harmonics and it won't shoot as well as it can.

On the optics, for all around use, ACOG's are tough to beat. A good TA01NSN will do everything you want. Larue QD mounts of course.

Rich

Is this a generalization or is there something wrong with SDI's fluting? :confused:

uscbigdawg
12-02-2007, 9:21 PM
I can't speak on SDI since I don't know who cuts their barrels (very few companies that sell barrels, actually cut their own barrels). This is definitely an in general statement.

I've been lucky with my rifles. I've got two that are fluted and they were cut by true "barrel 'smiths" that know how to do it right. After doing some testing though on other rifles we did track down some of the accuracy problems to the barrels. Could have been a bad run out of them being cut, but barrel blanks cut in the same run that weren't fluted yielded much better consistency and cold bore accuracy.

Ultimately, it comes down to how YOUR rifle shoots with that barrel and load. So, if you're confident in it, do not hesitate to get one. My AR's sport barrels from DPMS, JP, Oly and Colt (whoever cuts Colt's and DPMS's barrels). All have proven to be awesome with my JP and Oly barrels being sub .5 MOA rifles all day.

Rich

Jeffy
12-02-2007, 11:07 PM
I can't speak on SDI since I don't know who cuts their barrels (very few companies that sell barrels, actually cut their own barrels). This is definitely an in general statement.

Rich

I'd imagine SDI cut their own barrels. They are a US defense contractor for the M2HB Machine Gun variants. I believe they also make barrels for the M134 as well. SDI UK seem to have also bought all of the tooling from Parker Hail when they rolled over. They have offices in the US and the UK. This would make sense since they spell their names as one would in the UK.

Anyone else have anything to add about the upper combo?

uscbigdawg
12-03-2007, 1:44 AM
Major brain fart. Sabre is one of the few that do it right. Buy with confidence.

Rich

J_Rock
12-03-2007, 1:47 AM
See 'the chart'

http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/071120-AR-Comparison-Chart.jpg

FreedomIsNotFree
12-03-2007, 2:25 AM
See 'the chart'

http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/071120-AR-Comparison-Chart.jpg

Too bad Larue's Quad S isn't listed in that chart. I'm curious how it would rank. Of course I could just compare all of the details after researching it, but that would take some time.

Jeffy
12-03-2007, 12:27 PM
So SDI is pretty far up there. Some of those things won't apply since I'm not getting a bolt and the barrel SST and not Cro-moly. Also it's a middy so the H buffer is moot. So, it looks like if I take that into account it's about on par with LMT.

The barrel is from their SPR Carbine from the looks of it.

I was looking at handguard weights and it looks like I'd only be saving 2-3oz with the DD. Is that worth it? The Troy looks to be two pieces which would aid in installing a M203. Is there any other advantage of having the handguard lower come off easily?

Bladewurk
12-03-2007, 12:52 PM
I just built an SDI 18 inch Midweight Midgas Stainless Fluted 1in8 twist Barrel on a CMT M4 FT upper with Larue 13.2 foreend and it has near perfect balance and weight,functioned flawless so far through 60 rounds but no real accuracy testing yet.. gotta get out and put some of my hoarded BH TAP through it... your build sounds nice I'd just recommend the ACOG TA11 cuz I love the eye relief but you may want optic better suited to close range like an Aimpoint or Eotech..

Bladewurk
12-03-2007, 12:54 PM
The Larue HG is nice and slim and you can easily install yourself..no continuous top rail though..

Jeffy
12-03-2007, 2:47 PM
The Larue HG is nice and slim and you can easily install yourself..no continuous top rail though..

I don't have an action block or armorer wrench, yet. The upper I'm looking at is from PKF. They seem to be the only ones selling a 16" SS barrel. They also seem to be the only ones selling it with a SDI upper.

I've been pricing the parts individually and unless there is some additional discount, the assembled upper costs less then if I pieced it together myself. not to mention I'd have to buy the extra tools. (although I will eventually.) I asked them if they sell the upper without the handguards though. I'm waiting on what they say. I've subtracted the price of the Troy form their Troy package and get $435. Then I subtracted the DD from the DD package and get $408 for the exact same setup. So if that's the case the DD is the better deal and I'll just order that.

The LaRue Tactical 10 rail looks nice and has the quick release for the sling too. I'm starting to think that between Troy, DD and LaRue it really doesn't matter a whole lot. It comes down to who's name do you want to see.:shrug:

Jeffy
12-03-2007, 7:46 PM
Well, here's an update. I got an email from Brett at PKF. (btw: he's quick to reply.)


So if I don't want the handguard the upper will cost $420 + 30 to swap the CMT to a SDI upper. So according to that base price the Troy MRF MX costs about $205 as a package deal. The Danial Defense M410 comes out to $275. The cheapest I've seen the LaRue Tactical 10 was $286. Now factoring in getting a receiver clamp and a wrench it's not really worth it. Even though their Kool-aid is good. ;)

I guess next is a BCG...

As for an Acog, I'd like something with a bit more flexibility. I would really like to get a Schmidt & Bender Short Dot but they are way too much. Which is why I was considering something in the 1-5x tactical. I know I"d be giving up some speed up close but at distance it should be more accurate then an Eotech or Aimpoint. I did consider a 3x magnifier but they cost more then either an Eotech or Aimpoint. I can't believe how much they want for them. LaRue does have that Hensoldt 2.5X magnifier for a reasonable price though. I was also considering going with a LaRue Iron Dot instead of a rear sight. This would give me a inexpensive red-dot and BUIS to go along with the scope. Although, if I ever had to swap them out quickly, it could get complicated.

Also, taking into consideration the front rail, I'll have to get a cantilever mount for the scope, like the LaRue SPR and SPR-E.

532Fastback
12-04-2007, 5:34 PM
It doesn't matter if uppers are on the ban list right? Like if i wanted to buy a Colt upper?

bwiese
12-04-2007, 5:42 PM
It doesn't matter if uppers are on the ban list right? Like if i wanted to buy a Colt upper?

Uppers are not banned.

Most always it doesn't matter....

...however the one exception I can think of is that you should use care in not putting certain RRA uppers on an off-list RRA LAR-15 as that might have a change of being regarded as producing an "RRA Standard A2 carbine" or one of the other 4 or 5 banned RRA rifles. There is a ready defense for this, but it just make sense to use other combos.

532Fastback
12-04-2007, 6:33 PM
ok another question, what do more twists do for the overall performance of the gun? Colt's 20" upper has 1/7 twist stag 20" upper has 1/9, what does that mean to the perofrmance? will the 1/9 be more accurate?
I searched didn't find an explaination.

bwiese
12-04-2007, 6:44 PM
ok another question, what do more twists do for the overall performance of the gun? Colt's 20" upper has 1/7 twist stag 20" upper has 1/9, what does that mean to the perofrmance? will the 1/9 be more accurate?

Twist is connected to bullet weight (or more properly, bullet length- which trends with weight). Faster twists (i.e, smaller number in denominator) are for heavier bullets.

Fast twists on really light bullets can sometimes cause problems (45gr 223 in a 1/7" twist bbl).

Conversely, slow twists on heavier bullets can result in accuracy degradations. Original M16A1s with 1/12" bbls cannot really shoot newer 62gr ammo well - USGI manuals say that M855 ammo is for 'combat emergency use only" in M16A1s, dispersion is already lame at 100yds, with keyholing behavior.

1/9" is a good all-around twist, esp if you're shooiting common 55gr -68gr loads.

1/7" still shoots 55gr very well and is good up into the 77gr heavy bullets (i.e, 77gr OTM Sierra Matchkings, etc.)

For most folks' shooting with regular ammo you won't notice the difference...

532Fastback
12-04-2007, 6:49 PM
Twist is connected to bullet weight (or more properly, bullet length- which trends with weight). Faster twists (i.e, smaller number in denominator) are for heavier bullets.

Fast twists on really light bullets can sometimes cause problems (45gr 223 in a 1/7" twist bbl).

Conversely, slow twists on heavier bullets can result in accuracy degradations. Original M16A1s with 1/12" bbls cannot really shoot newer 62gr ammo well - USGI manuals say that M855 ammo is for 'combat emergency use only" in M16A1s, dispersion is already lame at 100yds, with keyholing behavior.

1/9" is a good all-around twist, esp if you're shooiting common 55gr -68gr loads.

1/7" still shoots 55gr very well and is good up into the 77gr heavy bullets (i.e, 77gr OTM Sierra Matchkings, etc.)

For most folks' shooting with regular ammo you won't notice the difference...

so a 1/7 twist will shoot normal ammo with good accuracy. Thats good to know. Thank you, you've been a lot of help!

isitkool
12-04-2007, 6:55 PM
Bill,

Would you mind posting a link for this...

or one of the other 4 or 5 banned RRA rifles. There is a ready defense for this

532Fastback
12-04-2007, 7:11 PM
not having any luck on finding a price for a complete colt upper, anyone know?

6172crew
12-04-2007, 7:20 PM
not having any luck on finding a price for a complete colt upper, anyone know?

They show up once and awhile. I have a 6920 complete rifle but the rifle was spendy and when they brake them up the uppers are spendy as well.

532Fastback
12-04-2007, 7:21 PM
They show up once and awhile. I have a 6920 complete rifle but the rifle was spendy and when they brake them up the uppers are spendy as well.

so its hard to get one then :(

PIRATE14
12-04-2007, 8:13 PM
so its hard to get one then :(

We had 6 6920 uppers but they have a 1/9 twist.....we do have one left and it's 849....

They pop up now and than.....

Jeffy
12-04-2007, 8:46 PM
Wow, my thread got jacked... :chris::Pirate:

532Fastback
12-04-2007, 9:00 PM
Wow, my thread got jacked... :chris::Pirate:

sorry it was on the 3rd page so i thought i'd use it real quick.

J_Rock
12-13-2007, 2:56 PM
Whats wrong with them? Please list so I can recommend changes :D

ar15barrels
12-13-2007, 11:43 PM
That "chart" is definitely not accurate by any means. I have personal experience w/ at least 3 of the uppers listed where the "specs" are WAY wrong!:eek: (unless I'm blind and have lost certain "senses")

Be very specific.
Remember that the chart is specific to one MODEL from each maker.
If you have a different model than the chart, you can't be calling the chart as being incorrect.

A lot of us invested a lot of time to get that chart to where it is.
Things do change though and the chart will certainly be updated to reflect current production if the manufacturer can show that they are improving by actually doing it.

Calls of chart inaccuracy will not be accepted without concrete proof.
Don't say I did not warn you... ;)

supersonic
12-14-2007, 7:51 AM
My bad! I did not realize the chart was based on a "model-specific" format. I can appreciate all the hard work that went in to the compiling of info to come up w/ this reference model for a specific example (Catalog #) of a complete rifle from , basically, the manufacturers that produce the highest quality rifles in the AR-15 family of weapon platform - more specifically, it seems, of the M4 variety (I must thank those involved for not including certain "bottom feeders!"(;)) in the final model). So, again, my apologies to the development team for not reading the chart more closely before posting my earlier reply.:) That being said, flaming in any way, shape, or form due to a realized error will NOT be accepted without concrete proof that said flame(s) is/are warranted.;):p
Scott

P.S. - Randall : you didn't warn me.